Diaphragm unit for loud-speakers



y 12, 1953 R. D. CHARLESWORTH' 2,638,509

DIAPHRAGM UNIT FOR LOUD-SPEAKERS 3 Sheets-Sheet 1 Filed Aug. 28, 19 48 m'm I 1 attorneys Mag :12, 1953 R. D. CHARLESWORTH 2,633,509

DIAPHRAGM UNIT FOR LOUDPSPEAKERS Filed Aug. 28. 1948 Baskets-SE91: 2

Cittorriegs y 1953 R. D. CHARLESWORTH 5 DIAPHRAGM UNIT FOR LOUD-SPEAKERS Filed Aug. 2a, 1948 s Sliefs-Shei; 5

ISnventor iii/#4100, cmmssmr/x Patented May 12, 1953 1;".

UNITED STATE S PATENT OFFICE DIAPHRAGM UNIT FOR LOUD-SPEAKERS Application August 28, 1948, Serial No. 59,323 In Australia August 2'7, 1947 2Claims. (Cl.179--115.5)

I This invention relates to improvements in loud speakers of the type in which a diaphragm carries a voice coil that operates in a magnetic air gap, and, in particular, relates to improvements in means and methods for constructing a diaphragm assembly unit that in itself is independent of and contains no portion of the particular magnetic unit to be used, although this diaphragm assembly unit is adapted to co-operate with the magnetic unit or units and particular locking means whereby eiiicient loud speakers are produced, and has been devised to produce a diaphragm assembly unit that is complete in itself and may be manufactured and used or stored for later use with particular magnetic units and locking members also of independent and individual construction and so that the individual units of a complete loud speaker may be demounted, inspected, cleaned, replaced or interchanged without the use of gauges, jigs, or special or precision equipment. In the following description and claims the words gauge or gauges include and cover jigs and the like.

In the formation of my improved diaphragm assembly unit I provide a diaphragm housing, a diaphragm to be secured to said housing and provided with a voice coil former and voice coil, 9. locating and supporting spider for said diaphragm and securable to the diaphragm housing and to the diaphragm.

The diaphragm housing may be formed of metal pressed or die cast or other stiff and relatively rigid material such as moulded plastic, and, preferably, in the approximate form of a frustrocone or the like, open at each end, with windows or similar apertures in its side walls; the larger outer end of this housing is outwardly rimmed or ledged to support the outer edge of the diaphragm to be used.

The housing side walls are formed or provided with an internally extending fiat ledge or shelf of any desired width which terminates in a preferably right angled backward extension of any desired shape, length and diameter; the rear end of this extension is formed or provided with a base and this base is provided with an accurately placed aperture of circular, oval, square, rectangular or other desired section. This aperture is adapted to positively co-operate detachably with a magnetic unit of the loud speaker to be formed.

An external outwardly extending flat member may be formed or detachably provided on the outer walls of the housing and, preferably, is secured to the inner flat ledge on the housing side walls e. H

The diaphragm to be mounted concentrically in the diaphragm housing is formed of suitable material, such as paper, and is, preferably, of frustro-conical, elliptical or the like shape and with an outwardly extending edge on its larger outer end to nest in the outer rim of the housing. The inner or apex end of the diaphragm is provided with a concentric neck and to this neck is concentrically secured, as by common practice, a voice coil former carrying a voice coil which is adapted to project through the housing base aperture.

A spider of any desired material in disc form and, preferably, corrugated, is formed or provided concentrically with a central aperture and with a cylindrical or other shaped neck of any desired length that is adapted to fit snugly about the diaphragm neck; the outer periphery of the spider is adapted to lie on and to be pressure cemented or otherwise secured to the inner flat ledge or shelf on the housing side walls.

To secure the spider so that its central aperture will be concentric with the vertical axis of the diaphragm I employ a spider gauge that has a lower cylindrical or other shaped base nesting a ring on its upper face. This ring fits from the rear exactly into the back open end or aperture in the rear extension of the diaphragm housing; a detachable central boss is fitted on the gauge, in some forms, concentrically with the ring and is of the correct size and shape to fit the neck of the spider. After the spider is positioned on and about this boss the outer peripheral edge of the spider is cemented to the fiat ledge on the inner housing walls, and when the cement has set the gauge is removed and replaced by a similar gauge that has a central boss of smaller diameter than that of the spider gauge boss and adapted to fit accurately the voice coil former. In practice, however, the central boss of the spider gauge may be removed and replaced by a smaller diameter central boss so that the gauge now may be used as a voice coil former gauge.

After cement has been applied to the diaphragm outer edge and the diaphragm neck, the diaphragm with voice coil attached is presented to the voice coil gauge and the voice coil former is slid on and about the boss until the larger end of the diaphragm is secured to the housing rim. The spider is also secured to the diaphragm neck. On removal of the gauge the assembled diaphragm unit is ready for use or storage. I

In a modified method and means for positioning the various members of the diaphragm assembly in correct concentric relation to each other and tothe diaphragm housing, the apex 3 ture in the housing base may be of any contour and of slightly larger diameter than that of the voice coil to be used; the whole aperture is not .necessarily concentric with the said voice coil;

the base of the housing is of any desired width and is provided-with a series of spaced holes which may be of any desired shape and size and on which gauges or the like may be positioned to align the spider and then the diaphragm and the voice coil in the manner; as; above. described. The said holes are adapted to detachably and positively co-operate with amagnetic unit. for the loud speaker to be formed.

In the accompanying drawing which. illustrate forms of construction ofa diaphragm assembly unit:

Fig. l is a rear half plan showing a housing, diaphragm, spider and voice coil and t similar half plan with the housing removed;

Fig. 2 is a half elevation and a half sectional elevation oii'the construction shownin Fig. i

Fig 3 is a sectional elevation of-a spider gauge;

Fig. A isa plan of the same;-

Fig 45A is a sectional elevation of; avoice. coil former boss;

Fig 4B is a sectional elevation of a. modified ermo i pj er auge;

Fig.5 is aplanof a diaphragm housing with a modified. e me basei F s. a. ent l.- ecti nal" e evation o i' sfl- A diaphragm housing W, formedwith an-outer 11A. and. Windows. 1B s. form d. or. p ided-.0 1. n er si e wal s. ith. a. a fl t unha nel ed. ed e, she i i that is p ov ded wit ots HA pre erably n uate: in. m. o funct on. as. art loekingg mbers, of" me nsfor loc inatheunitsoi. o d sneak r. each. ther a te s em ly- The.. .1 ..1 is orme 0.1. proided w th a y indrical xtension. M on the shelf edgeat light angles toshelff ii... The Grim.- d iea ex ens on-mar be v p. ace lby an. extension of any, esiredz r s s ction. nv eacho sea base I] C of any, desired Width. is. formed. or. pr v ded n the ear endo he. xtensionand. is. provid d withanape ture. NE; in .thepreferred. fo m eon: centr c w th. the edge Li; ancl' lustrated. Fi s 1,. and. 2.; aseoneentricwith theledge H; anclthe outer. im A, of the-housing. and; is dapted to ete hab y. c v oe atewit .almaeneticunitwith:

out. the, aid. off assem ly sweeaiissor theJike, 0

when the; individua members f a loud peaker are. be n a semb ed. In ther forms; of. con: r eti ashewnim E esi 5.. and..Gfihebaseisnrm ed, with. a,.s.. es.of spa ed. holes. I i1). 011 ny esir d h p nd. sizewhich .hol smay. etach: ab y. q p rfienmitiwly. w th a ma neticunit w t outt 'e se f a es. iieae lelike,i'nthe omplete. an ioa 'a s mbly. ofia. ou speaker.

4 with a concentric neck |3A that is adapted to be cemented to the diaphragm neck 12B, and also is provided with a fiat peripheral portion I3B adapted to be cemented to the housing inner shelf II.

The. spider is positioned: on the housing by means of a spider gauge (Fig. 3) that carries on its base plate a ring 130 that is adapted to make a close fit in the rear housing aperture HE. A removable-central. boss M preferably concentric with ring 130 is adapted to take the spider neck 13A and, when the spider is positioned on the gauge. its, periphery MB is cemented to the shelf ii. The. boss; 1-4 is then removed and replaced by a smaller diameter boss M (Fig. 4A) adapted tofltclosely the; voice coil former 62C when the diaphragm is presented to the gauge and housing. Cement is. applied to the outer rim of the diaphragm and to the diaphragm neck before the diaphragm is positioned on the gauge.

In a modified method and meansfor correctly assembling the structural members of the diaphragmassembi'y unit the base. N0 of the housing isprovided withaseri'es of spaced holes MD preferably/concentric withtheinner ledge H and the housing'rim WA; the aperture ME in this base is of any desired contour and'of sufli'cient size and situated" to clear. the voice coil. As shown in Fig-413a gauge similar to that shown in Fig, 3- an'diihaving a removable central boss Hi withinthejring |:3'C;that is provided with aspaced series; oi; studs MB that. engage positively the holes i=1D5lndSO that the boss. MI is. in concentrio relation to. the vertical. axis. of the. housing andfitsztheneck ofthe spider l3. Thespider is then cemented to; the shelf it. By. the use of a substitutedivoice. coil" former boss 5 for theboss M" the voicecoil' former. may be. correctly positioned and the spider cementedfto. thediaphragm neck- I23: and the, diaphragm to the. housin rim 4 0A.

By either of thesecentring means and. methods h Vertical. axis, of. the spider... the. longitudinal axis ofthe voice, coil former. and voice, coil.v and P the centre, irrthe, housingbaseare brought into tamed. the...- naturev of this, said. invention, and. in

An o t l xtendingflange HF. shownin Fi asdet ha 1e.is pr vided. with. nartiockring members such asslots I Thefiangemay be integral with the outerWallsof thahonsins I it adapted tamake. a..close fit.- on,it s. .cy1indrioal outer portion .132; in, the. rear. ousing. aperture. LLE. as thebase lJCisisea-teo in. p rtiontaei marine? 3Q,

rustmonical. or he .-1i e;diaphraem. ithes on itslareerout r. nd anedsa l Za hatisio be secured to h u i g; m; M. The nnen r. p x end of thediaphragm is provided; with-acumentrio neck. 1.23am which issecured in known. mam nor a. voiceeoilv former HQ and. voicecoil' 12D thatprOJ 6011., through .the aperturain 5 the. nous: ma aseai corrugatedsp idw 1.3;; isiormed. or. presided;

' What..-manner. thesameisvtobe, performed, I de-.-

clf rethat. what]; claim is;

Ii l niaioudusp eaker a diaphragm assembly unit comprising in combination a... diaphragm housius...having, a. base and. being provided, with anvaccuratelfy oositionedaperturein itsbase, a diaphragm attached tot said. housing and. fitted withia voice. coil? f,orme1:,,,a-.voice..coil, carried by said voice. coiLiiormer, and allocating and supporting spider.v attached, to. said. diaphragmr-and tmsaidlhoming, said. ;1iousing ..ha.v ing, an .inwardly, extending flat; ledge on. the side. wall, portions thereof,..alrightrangledrextension on the. radially inner. edge... of. the. led e. and the. said. basefor the... extension. containing, that aperture is accin'ately positioned with relation to th-evoice coil former said ledge carryingsaid spider and having partlocking; meansprovided therein, so that the. individual. parts. of the; complete; diaphragmsassemblyv area in: concentric relationship to each other and the voice coil is in correct ,opers ative alignment with the aperture in said base, said flat ledge having a plurality of arcuate slots provided therein to form said part locking means, which slots are concentric with said aperture in said housing.

2. In a loud speaker, a diaphragm assembly unit comprising in combination, a diaphragm housing having a base and being provided with an accurately positioned aperture in its base, a diaphragm attached to said housing and fitted with a voice coil former, a voice coil carried by said voice coil former, and a locating and supporting spider attached to said diaphragm and to said housing, said housing having an inwardly extending fiat ledge on the side Wall portions thereof, a right angled extension on the radially inner edge of the ledge, and the said base for the extension containing the aperture which is accurately positioned with relation to the voice coil former, so that the individual parts of the complete diaphragm assembly are in concentric relationship to each other and the voice coil is in correct operative alignment with the aperture in said base, and an outwardly extending ledge member secured to said ledge and having part locking means provided therein for engaging a magnetic unit.

REGINALD DENISON CHARLESWORTH.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Hardisty Apr. 25, 1933 Jensen June 2, 1934 Quam Nov. 5, 1935 Quam Nov. 5, 1935 Jensen July 7, 1936 Creager Apr. 25, 1939 Sundstrom Sept. 26, 1939 Neuschotz Apr. 16, 1940 Stone et a1. Oct. 21, 1941 Knowles Sept. 8, 1942 Marquis June 24, 1947 Knowles Oct. 21, 1947 FOREIGN PATENTS Country Date Great Britain June 29, 1931 Great Britain June 23, 1932 Great Britain Jan. 20, 1937 Great Britain Jan. 4, 1939 Great Britain Dec. 15, 1947 

